Comparison of single-phase transformerless photovoltaic grid-connected inverter topologies with high efficiency and low ground leakage current

When a transformer is taken out of a photovoltaic (PV) inverter system, the efficiency of the whole system can be improved. Unfortunately, the additional ground leakage current appears and needs to be considered. The problem of ground leakage current is that it poses an electrical hazard to anyone touching the photovoltaic (PV) array's surface. For safety issues, the ground leakage current should be less than 300 mA, which follows the VDE-0126-1-1 German standard. To minimize the ground leakage current in the transformerless PV grid connected inverter system, the proposed inverter topologies (SC-HB inverter, bipolar H-Bridge inverter with CD-Boost converter, modified unipolar HBridge inverter with CD-Boost converter and modified unipolar H-Bridge inverter with modified boost converter) are analyzed, verified and compared in this thesis. In order to analyze the effect of unbalanced filter inductance on the transformerless bipolar H-Bridge inverter topology, the matching ratio of inductance :Lr = Lfl/Lfln and L12IL12n ) is investigated. In addition, the effect of parasitic capacitance value on the transformerless bipolar H-Bridge inverter topology is studied. The effect of modulation techniques using bipolar SPWM and unipolar SPWM on the transformerlcss H-Bridge inverter topology is compared and analyzed in terms of common-mode voltage and ground leakage current. TMS320F28 I 2 is used as a controller to generate the PWM control signal, maximum power point tracking (MPPT) based on power balance and Proportional-Integral (PI) controller. PSIM 9.0 simulation software is used to design the proposed transformerless inverter topologies. Simulation and experimental results verified the proposed inverter's feasibility in addressing issues of transformerless DC/ AC converters in grid-connected PV systems

Study of glycerol electrochemical conversion into addes-value compounds

The price of crude glycerol has significantly decreased worldwide because of its oversupply. Many chemical and biological processes have been proposed to transform glycerol into numerous value-added products, such as glycolic acid, 1,3-propanediol (1,3-PDO), 1,2-propanediol (1,2-PDO), glyceric acid, and lactic acid. However, these processes suffer from several drawbacks, including high production cost. Therefore, in this study, a simple and robust electrochemical synthesiswas developed to convert glycerol into various value-added compounds. This study reports for the first time the use of Amberlyst-15 as a reaction mediumand redox catalyst for electrochemical conversion of glycerol. In the first part, the electrochemical performance of Amberlyst-15 over platinum (Pt)electrode was compared with that of conventional acidic (H2SO4) and alkaline (NaOH) media. Other parameters such as reaction temperature [room temperature (27°C) to 80 °C] and applied current (1.0 A to 3.0 A) were also examined. Under the optimized experimental condition, this novel electrocatalytic method successfully converted glycerol into glycolic acid after 8 h of electrolysis, with a yield of 45% and selectivity of 65%, as well as to glyceric acid after 3 h of electrolysis, with a yield of 27% and selectivity of 38%. In the second part of this study, two types of cathode electrodes, namely, activated carbon composite(ACC) and carbon black diamond (CBD) electrodes, were used in electrochemical conversion of glycerol. To the best of our knowledge, electrochemical studies of glycerol conversion using these electrodes have not been reported yet. Glycerol was also successfully reduced to lactic acid, 1,2-PDO, and 1,3-PDO, in addition to oxidation compounds (e.g. glycolic acid). Three operating parameters, namely, catalyst amount (6.4% to 12.8% w/v), reaction temperature [room temperature (27 °C) to 80 °C], and applied current (1.0 A to 3.0 A), were tested. In the presence of 9.6% w/v Amberlyst-15 at 2.0 A and 80 °C, the selectivity of glycolic acid can reach 72% and 68% (with yield of 66% and 58%) for ACC and CBD electrodes, respectively. Lactic acid was obtained as the second largest compound, withselectivity of 16% and yield of 15% for the ACC electrode and 27% selectivity and 21% yield for the CBD electrode. Finally, electro-oxidation and electroreduction of glycerol were performed in a two-compartment cell separated by a cation exchange membrane (Nafion 117). This study only focused on the electroreduction region. Three cathode electrodes (Pt, ACC, and CBD) were evaluated under the following conditions: 2.0 A, 80 °C, and 9.6% w/v Amberlyst-15. ACC demonstrated excellent performance in the electroreduction study and successfully reduced glycerol to 1,2-PDO, with a high selectivity of 85%. The selectivity of 1,2-PDO on Pt and CBD was 61% and 68%, respectively. Acetol and diethylene glycol were also obtained. The reaction mechanisms underlying the formation of these products are then proposed

Konsep Al-Shifa' dalam Al-Quran : kajian terhadap metode rawatan Ibn Qayyim Al-Jawziyyah

This study employed an analytical analysis on the methods of therapy of Ibn Qayyim based on his writings. It was aimed at understanding and analyzing the thinking of Ibn Qayyim in his medical therapy which comprises the physical and spiritual aspects as well as the influence of the sorroundings of his on his style of writing. On the other hand, the specific objective is to uncover Ibn Qayyim’s views toward the six ayat al-shifa’ (verses of healing) in the holy Quran and his concept of al-shifa’ (healing) derived from the Quran and al-Hadith. The study also scrutinized his principles and methods of therapy and medicinal school of thought. As a result, the reseacher was able to formulate a model of Ibn Qayyim’s therapy methods as well as indentify the elements to be evaded while practising the method. The method of study was thematic and hermeneutics analysis as well as philosophical interpretation. It was found that Ibn Qayyim being a respected Muslim scholar was able to boldly promote an Islamization to the medical discipline which is more holistic in nature. In order to balance the scholarship thinking culture and societal needs, he uses the approach which was spiritually value laden and emphasizes ishtibak (traversity) in the medical practice. This is so to establish revealed sources as the primary reference with the human sources as secondary references in the al-shifa’ method of therapy. Through his method of therapy, Ibn Qayyim was able to show his inclination towards the development of spiritual potentials and inner faculties of a human being in achieving healing

Smart learning environment system: e-Commerce module / Saw Yuen Meng @ Chua Yuen Meng

Smart learning environment system is a system that allows the maintaining and distribution of course materials via the web, administering and grading test for web-based courses, facilitates multilavel threaded discussions among student to student or student to lecture, manages the system and databases for the web-based courses and streamlines the ordering and purchasing of learning materials for web-based courses. This proposal is fully concentrated on building a system for the ordering and purchasing of learning materials for web-based courses. The main objective and significant of the system is to be easily integrated in the smart learning environment system. The learning materials here are computer related books. The system is also known as e-Commmerce Module and is divided into 2 modules, Consumer Module and Admin Module. Consumer Module itself is also divided into 5 more modules there are Order Module, Review Module, Search Module, Register Module and Login Module. While the Admin Module is where all the administartive work is conducted such as deleting, editing and adding new materials into the system. It also consist 4 more modules called Edit Item Module, Edit Review Module, Edit Member Module, Report Module and lastly Category Module. The approached in building the system is based on prototyping and the tools and software that were used to build the system is based on the Open Source concept that is software that are feerly distributed. The software that were used to realized this system are Java, MySQL database, Linux Operating System and Apache Web Server

Online Psychological Testing System (OPTS) / Tan Kien Leong

Online Psychological Testing System (OPTS) is an Internet-based system aim at provides a central place on the Internet to give information about the practice of psychology knowledge to the user. The system architecture for OPTS, which is developed in web-based can be divided into client (web browser), web server and database server. Before developing OPTS, researches have been done to understand various new concepts, which are relevant to this project. Among the topic are psychological questions, Internet, client/server concepts and other relevant topic. Questionnaire is used to get the feedback from the students in University of Malaya about their opinions with this project. Methodology used to develop this application is prototyping, where part of the system can construct quickly to understand and clarify the requirements and designs of the system. OPTS can be divided into 2 sections, which are the Student and Administrator. At the end of the project, OPTS will expect to have security checking for authorized user, develop database to keep all the records, create database maintenance and creation of interactive homepages to deploy information to students. OPTS is developed using Active Server Pages technologies on the Microsoft WindowsNT platform utilizing database created and stored from Microsoft Access 2000. It is believed that this web-based database system will gradually become an essential to everyone in the future

Chinese associations with particular reference to the surname, province and district associations / Low Lai Sheong

The purpose of this study was to gain some insight into the status and workings of Chinese associations at present as compared to the past. In this study, only the surname (tsung tsai), district and provincial associations (hui kuan) are considered. Chinese associations have existed for a long time and the oldest association established in Selangor dates back to 1865. This study is confined to those located in Kuala Lumpur. The data was collected by interviewing the secretaries of the associations. In this study, the secretaries of the 43 Chinese associations in Kuala Lumpur were interviewed to obtain information on several aspects of the associations. The aspects touched were to see whether Chinese associations have adapted to the times or not; present and past functions of the associations; membership characteristics; nature of leadership, financial status; nature of social mixing; available facilities and attempts if any to keep uo with the times

China’s corporate tax management and its economic consequences / Zhang Chen

Since economic reforms began in 1978, China’s enterprises have undergone considerable changes. So too have the taxation system have experienced major reforms over the last three decades to closely resemble those of the market economies, which included the introduction of corporate income taxes in the country. Since corporate tax is a significant cost to enterprises, firms have introduced corporate tax management to strengthen financial decision-making. The extant theories on corporate tax management have not always been consistent, which is more so with the empirical evidence from China given its unique transition from a socialist structure to one where the market have gradually increased its role in the economy. Given the complexity of the economy and still paramount role of the state in the economy there are still loopholes that corporations often exploit to their advantage, which may make tax management in Chinese listed companies inefficient and unpredictable. The central objective of this study is to analyze the economic consequences of corporate tax management in China. In doing so, the study posits the following three research questions: firstly, what is the impact of corporate tax management on firm performance and how tax management can help maximize firm value?; secondly, what are the market outcomes of corporate tax management and how does government ownership influence these outcomes?; and thirdly, what is the impact of corruption and marketization on corporate tax management, and how do they affect firm performance? The results show that that corporate tax management has a negative direct impact on firms’ market value, which support the agency theory of tax management. Nevertheless, corporate tax management can promote market value through the indirect improvement of firms’ profitability and growth, which suggests that tax management can help but they need the deployment of a sound and effective corporate governance mechanism. Next, the findings show that corporate tax management has the potential to cause adverse future market outcomes so as to cause stock price crashes, which support the bad news hoarding theory. The evidence shows that state ownership cannot alleviate this crash risk. Indeed, municipal listed state-controlled enterprises are more likely to face future crash risks than other enterprises. Finally, the findings show that corruption affects corporate tax management non-linearly in China, which support the theories of “grabbing hand” and “helping hand”. Moreover, corruption positively affects the performance of corporate tax management. Furthermore, marketization helps to mitigate the impact of corruption on corporate tax management at both phases of the inverted U-shaped curve. Overall, the thesis shows that corporate tax management is an important financial strategy that can be designed to enhance the wealth of shareholders. However, due to agency problems, the real consequences of tax management have remained uncertain. The solution to addressing agency problems is to bolster enterprise management with sound internal corporate governance through effective coordination with external markets and institutional development

Third person reference in Hong Lou Meng and its English translations / Zhang Yanan

The aim of this research, specifically, is to compare and contrast the different usages of third person references applied in the Chinese ST and in its two English TTs. The Chinese novel Hong Lou Meng and its two English versions entitled ‘A Dream of Red Mansions’ and ‘The Story of the Stone’ are used as main data for this current research. The sources which contain the third person reference found in the first three chapters of these three books were collected from both the original SL text of Hong Lou Meng in Chinese ST and the two translated TTs in English. One hundred and ninety-eight sentences including third person reference from the first three chapters of each book were extracted and coded to ease analysis. Halliday and Hasan’s (1976) taxonomy of third person reference was used to identify the different categories of third person reference. Besides, the different ways of translating third person references employed in the two English versions were also further explored according to Reiss and Vermeer’s (1984) Skopos theory. Findings of this study reveal that the numbers and types of third person reference found in the Hong Lou Meng and its two English translations are shown differently. Furthermore, this study also indicated that the two translators of Hong Lou Meng have different Skopos and translating style. The way of translating third person references in the two target contexts was construed differently based on their own translated version of Skopos as well as their Chinese or Western cultural influence. As a result, the analyzed data has shown that the level of TT’s explicitness is much higher than that of ST’s, and the level of T2’s explicitness is even higher than that of T1’s

Seabed scour induced by twin-propeller ships / Yew Wan Tian

To date, higher power ships are extensively used in order to fulfil the maritime trading demand. The resulting high velocity thrust produced by ship’s propellers or side thrusters has seriously eroded the seabed. Ship-Twin-Propeller (STP) is a ship equipped with two propellers. It has improved powering system, handling system, ship stability, and ability to propel the ship faster as compared to single ships. These advantages have increased the demand for STP among the marine traders for higher profitability and efficiency. This study involves experimental and virtual simulation works. Laboratory experiments were designed to investigate the axial velocity profile of selected rotating STP and the resulting scouring actions; whereas, the Computational Fluid Dynamic (CFD) model simulation was used to observe and estimate scouring pattern. The existing theory and experimental results were mostly derived from plain jet and single rotating propeller. This study has enhanced the understanding on the scour mechanisms and relationships of STP’s velocities impingement on the seabed. The asymptotic scour induced by STP profile was defined in four stages, which are (i) initial stage, (ii) developing stage, (iii) merging stage and (iv) asymptotic stage. An equation is proposed to relate between the parameter, namely the densimetric Froude number, the clearance ratio and the reference time scale for the prediction of maximum scour depth and also the maximum scour location. The proposed equations were found to be highly correlated with the observed parameters. Moreover, the proposed CFD and experiment model have given representative data in graphical method to simulate the scouring pattern at different sections for better scour estimation and visualisation. Therefore, it is able to assist design engineers and port authorities in designing the protection structure against scour erosion. Moreover, this will also help in designing the bathymetry level, so that the designed level would be maintained to minimise the dredging or filling sediments costs

The timeline of forest management in Malaysia towards achieving sustainable development goals / Noranida Mokthsim

Malaysia is committed to sustainable forest management (SFM) and this is reflected in the progress made on forest matters since UNCED. The National Forestry Policy was adopted in 1978 and revised in 1992, while the amendments of the National Forestry Act 1984 (amended in 1993) accorded greater emphasis on environmental protection and conservation of biological diversity. This dissertation presents a timeline approach in examining the relationships between forest resource development, forest degradation issues, and Malaysia’s efforts toward achieving sustainable development. The aim of the study was to examine from a timeline perspective how Malaysia’s growth trajectory, as determined by the utilisation of forest resources, had led to not only growth and expansion of its economic base as a common feature of development, but also the emergence of forest degradation issues. Four research objectives were established to answer the research questions in this study. The first objective was an examination into forest resources development in Malaysia, while the second objective was identification of forest management strategies undertaken by Malaysia. The third objective was to evaluate the effectiveness of the existing forest management strategies and the final objective was to identify the challenges in forest management related to forest resource development. To answer these objectives, data were collected from primary and secondary sources, where qualitative analysis was used to analyse the primary data and document analysis was adopted to analyse secondary data. The findings showed that the consumption of forest resource in Malaysia and the size of forest areas changes through time. In depth interviews with 10 respondents from different cohorts revealed the same opinion, which was that Malaysia cannot achieve sustainable development by 2020 if no alternative action is taken. The Strength, Weaknesses, Opportunity, and Constraint (SWOC) analysis was employed to determine various aspects relating to forest management in Malaysia. The last two decades also witnessed the increasing impact of trans-boundary problems in Malaysia that include both regional and global issues. These trans-boundary issues create another dimension that needs to be addressed in forest management, since at the national level, forest management faces tremendous challenges that need to be overcomed. Trans-boundary issues are difficult to manage because it affects many countries that have different priorities in their development of forest resources. Malaysia’s approach toward forest management is basically a three-pronged strategy that deals with management at the National, Regional, and Global levels